Composite switching device



May 24, 1949. D AN 2,471,200

' COMPOSITE SWITCHING DEVICE Filed June 16, 1945 4 Shee'ts-Sheet 1 INVENTOR. \A/lllldm Deans AT TOR NE'YS' May 24, 1949.

w. DEANS 2,471,200

COMPOSITE SWITCHING DEVICE Filed June 16, 1945 4 Sheets-Sheet 2 INVENTOR. wllham De ans ATTORNEYS y 24, 1949- w. DEANS COMPOSITE SWITCHING DEVICE- 4 Sheets-Sheet 3 Filed June 16, 1945 INVENTOR. Walladm Deans ATTORNEYS 'May 24, 1949. w. DEANS COMPOSITE SWITCHING DEVICE 4 Sheets- Sheet 4 Filed June 16, 1945 INVENTOR. wllllam Deans ATTORNEYS Patented May 24, 1949 COMPOSITE SWITCHING DEVICE William Deans, Ridgewood, N. J., assignor to I. T. E. Circuit Breaker Company,

Philadelphia,

Pa, a corporation of Pennsylvania Application .l'une 16, 1945, Serial No. 599,844

3 Claims. 1

My present invention relates to circuit interrupters and more particularly to a composite switching device adapted for use in electrolytic processes, as for instance in the manufacture of aluminum and magnesium, wherein electrolytic cells are used for melting and purifying of the metal. These electrolytic cells take large currents at 5 to 8 volts, a number of them being connected in series and fed from a 600 volt source. When one of these cells is taken out of service for re-lining or repair work, it is necessary to short circuit the bus around the cell.

My novel device is particularly adapted thus to by-pass the bus around an electrolytic cell connected in series with other electrolytic cells in an aluminum or magnesium manufacturing process.

Where it has been necessary in the past to disconnect cells for any purpose, this has been done by driving a large copper wedge between sections of the bus in order to by-pass the cell. When the cell is completely repaired or replaced and put back in service, the wedge is driven out by a mallet. Occasionally when a cell is put in service, good contact is not made in the cell and this results in opening a full current at 600 volts on the wedge resulting in a large amount of arcing.

My invention contemplates the provision of a composite switching device which will eliminate the necessity for following the dangerous procedure of driving the copper wedge between sections of the bus and the even more dangerous procedure of removing the wedge after the cell is replaced.

The type of device which my invention contemplates is one which will short circuit a 70,000 ampere current at 8 volts and also one which may be opened safely on such current at even greater voltages.

Essentially my invention provides a plurality of manually operated switches in parallel with each other and so arranged and mechanically interlocked that they may be closed or opened sequentially only--so that the opening or closing of the circuit will be in a step by step manner. These manually operated switches are arranged in parallel with a circuit breaker which may be closed manually but which may be tripped electrically from a remote point.

When it is necessary to remove an electrolytic cell from the cells in series and thus when it becomes necessary to by-pass the cell, the switching device with all switches open is moved up to and connected to the bus on either side of the cell bypassing the cell. 1

The circuit breaker is closed first establishing a circuit across the cell. The manually operated switches are closed in predetermined sequence, the first manually operated switch establishing a second circuit across the cell and each successive switch establishing another parallel circuit across the cell. This is the equivalent mechanically of driving a wedge between buses since as a wedge is driven in, better and better contact is made as the Wedge is driven more tightly. Here by sequentially closing successive contacts, more and more circuits in parallel are established across the cell so that finally the circuits in parallel may readily take the full load of the system.

The cell may then be disconnected and removed for replacement or repair. On replacement of the cell the switching device is operated in reverse order to open the parallel circuits successively and the circuit breaker is tripped last from a point remote from the circuit breaker in order to protect the operator.

On final tripping of the circuit breaker, the cell takes the full load once more and the switching device may be disconnected and removed. This opening operation of the switching device is again the equivalent of driving out the wedge where as the wedge is driven out, the contact becomes poorer and poorer until the Wedge is finale ly removed. However, since a circuit breaker with an arc extinguisher performs the final disconnecting operation, any arc which may possibly be drawn owing to poor contact within the cell, is confined within the arc extinguisher which is designed to extinguish the arc with speed.

By this step by step arrangement, a plurality of switching devices Which individually may handle much less than full load may be used in place of a single switching device which would be extremely large and cumbersome. The sum total of the weight and cost of the plurality of switching devices is much less than the weight and cost of a single switching device required to handle the full load.

Further, by the use of the multiple switching device mounted in a single unit, a step by step connection and disconnection of the parallel circuits across the cell may be obtained.

A principal object of my invention, therefore, is the provision of a multiple switching device with interlock means thereon to ensure predetermined step by step sequential operation of the switches either to open or close a circuit.

Another object of my invention is the provision ,tion of my: noyel switching=device.

of electrolytic cells I0, II and I2 in series arefedby bus conductors-43,14 from the feeders I5, I6. ,The-electrolytic-cells .Ill, I .I, -I-2 are connected with each other and. with ,thebus conductors I3, I4 .by short bussections I 1, -18, I 9, 20.

of a switching device adapted to be placed across an electrolytic cell in an electrolytic process to short circuit the cell so that the same may be removed for replacement and repair, the said switching device providing step by step means for connecting and disconnecting by-pass circuits around the electrolytic ce11 sequentially.

Another.-obi;ect. ofsrny inventionis the provision of novel-mechanicalinterlockmeans'for a multiplicity of switching devices.

The foregoing and many other objects of my invention will become apparentin the following description and drawings in which Figure 1 is a view in perspective .of mynovel switching device embodying. sin-manually operated knife switches and a circuit breakerwhich may be manually closed but which may be tripped from a remote point.

Figure 2 is a front View Of the switchingdevice of Figure 1.

;Figure,3 isasideview partlyinflsectionpf the .lswitchingdevice taken from line,.3.3.-of Figure 2 looking in the directionofthearrows.

"Figure l is ,r=t,.sfid.e.v view .partlyin sectionof the H switchin device of Figures Land 2 taken on line ie-e4, of-Figure.2, looking innthedirection of the arrows.

Figurei a .top. view of the switching device of Figure 1.

Eigurecii.is-a circuit diagram illustrating the; .cperation, of my. novel. switching --device.

1 Referring first .Ito Figure I .have here shown a simple circuit diagram illustrating the opera- A plurality Assuming now: that the-electrolytic cell -I -I is to be removed .forr any purpose, .my novel switching device ZI is moved upradiacentto-cell H .and con- 1 ductors; 22,- ,23 of the switchingdevice-Z I are, con- 1 .nected toh-husyqsections I-8,..I9- across. the call I I. switchestare --open-:--in th switching device 2 I at this time. wGonnecti-ng member 22-is connected ,to the ;bus F2-4 in the, switchingqdevice and connecting membert-23 is-"con-nected to the bus 25 in the switching device.

*Iihe operator firstcmanually. closes the circuit breaker 30 which closesa t e circuit ;3 I between .busesil arrd:; -25=so. that a; single-circuit through yconduetor. 3 I is-esta-blished across the tell I I The operator, thenclosesswitch-SZ toconnect the con- ;clucton flat-across thejouses 24 ,zandz 25 and hence across the cell II, and then sequentiallycloses switches: 33, .34; 1-35 136, 31. At the completion of thisrop ra icm *ClIGllillS are establishedi through the six switches .32-41 and the --circuit-,breaker;230. m y; now-be disconnected from; the bus section :18; i9 andremoved. forreplacement or repair.

iwill' zbe'zseenthat seven ,parallel The cell 1 l -,When the call, I -I 1 isreconnected: then the *se- :quencev f or aopening, theiswitches. as 'determin'ed by the mechanical interlock herein described is as "follows: Switches 331., :36,' -35,;34,'-33 and132 are .yopened ,in ,thep order inamed and then the :circuit breaker '3 I! .:is tripped open' from a==remote point.

When all. .or. the switches ofith'e circuit: breaker are opened,-:ce1l: I I takesthe "full? load and consnectorsrztand 23.may-bedisccnnected"from the :buses +I8 land19==andthe switching :devicerem'oved.

- singlefisw-itching device 2-l may-be perm-aestablish the parallel circuits so that the cell II may again be removed for test. If, however, after the switches all open, circuit breaker 30 trips with no arc, or practically no are, then that is an indication that the cell II is now in proper .condition and .the switching device 2! may be disconnected and removed.

The essential element of my invention is that the switches are so interlocked that they cannot be opened simultaneously or that two or more of them 7 cannot be "opened-at .one. time. They must --be opened sequentially, one :circu'itv bein 7 broken before the next one is broken. and they can "be opened only as fastas an operator may move from switch to switch to .open the same. This. is-achieved by -the., particular mechanical inter-lock clearlyshown in the remaining figures.

In Figures 1 and, 2.- I have shown the switches 32 to 37- respectively :as: knife switches otthe type shown in Patent No. 2,246 072, assigned: to the-assignee of the present invention: and the circuit breakenBD-as acircuit breaker of the type shown in Patentt-No. 2555,0 15,alsoassigned to the a'ssig-nee-of theppresent invention. .The base of the switching device:2-I comprises a longitudinal-channelM.,mountedrbetweenapair of cross channels AI, 42. Cross channels 4|, 42-carry channel shaped standards 43,-? 44 suitably :sup- ,ported by vflanged.lzrrackets 45;45'011 the base -4El -4I42. -:Standards-.43-44 w-hich are channel shaped, as above pointed-out, have secured to the back thereofany .suitable cmannergas for 'ginstance: by bolts 41, insulating ;:plates- 48. The insulating; plates carry sbuses id, 25-which are secured; thereto .also. in: any. suitable manner byboltsimountedin recesses.- 5 Ivor; the :insulatingplates '48.

. The buses: 24 and- 25 :as' shown vinE-Fi'gtlre each comprise a pair of, parallel channel: sections :with

:the flanges of the channels 'directed toward each other. This isa. common sbus construction.

I Each of the knife switchesxfls supported; between the: :buses'; 25: as shownzzpanticularlyin Figure 4, wherein it is seen that the knireswitch :32. has 'aiT-shapedpterminal eblock: fi-llyhav-in'g" the cross, plate'JIiI ,--which in tum.is:.-connectedto;the

angle plate-.63. 'Angl'e'plate163 is'securedz totthe bus and establishes. contactith'erewith. ne.0f the six angle plates 63 is extended at 631mm furnish a connecting means ior 'connector:ij.-22t(see The'op'erating. emmCBB is rotatably moimtedin any suitable manner onthe aterminals bloc'kx "50 and is provided with a-zhand'le B l; :ior appropriate rotation or. the operating arm 366 NVFilShTGSDEGt'JtO shaped; having the cross plate-13.

Cross plate 13 :aof the hyper terminal -hlock :12 is connected to the connecting late i l-Whibhihterconnects the two channel sections of bus 24. One of the plates 14 has an extension 14a for connector 23 (see also Figure 6).

Accordingly blocks 60 and 12 act as the stationary contacts and the clamping members are the bridging contacts of each knife switch. The switch herein shown is more specifically described in Patent No. 2,246,072.

It is desirable that the switches be operable in a predetermined sequence. To this end each of the handles 66 of the switches 32 to 31 is provided with the cross bar 80 (Figures 1, 2 and 5). Each cross bar 80 in the specific embodiment shown in Figures 1, 2 and 5 is provided at its left-hand end with a recess 8| at the front left corner and a tongue 82 at the back left corner. Obviously the cross bar of the knife switch 31 requires no such tongue or recess on the left-hand end.

Each cross bar 80 is also provided at its righthand end with a tongue 83 at its front right corner and a recess 84 at its back right corner.

As shown in Figures 1, 2 and 5, the right-hand tongues 83 on each cross bar 80 register with the left-hand recess 81 of the adjacent cross bar 80 to the right thereof; and each left-hand tongue 82 registers with the right-hand recess 84 of the cross bar to the left thereof. Obviously the knife switch 32 which has no switch to the right thereof does not require a right-hand tongue extension.

It will thus be seen that in the embodiment shown, knife switch 32 must be closed before knife switch 33 can be closed. Any attempt to close the knife switch 33 before knife switch 32 is closed will result in the cross bar of knife switch 33 striking cross bar of 32 and pushing the knife switch 32 up.

Since the knife'switches are designed so that a specific manual force is required to close the same, this will double the amount of force necessary to close knife switch 33, and the operator will then desist from closing knife switch 33 and will first close knife switch 32. Accordingly, the arrangement of tongues and recesses of cross bars 80 requires that the knife switch 32 be closed first and then sequentially switches 33, 34, 35, 36 and 31. Circuit breaker 30 is closed as above described before any of the knife switches are closed.

During the opening operation it will be clear that knife switch 32 cannot be opened first because any attempt to do so is blocked by all of the closed knife switches 33 to 31. Accordingly the operator must first open the knife switch 31 and then knife switch 36, and sequentially down to switch 32. The trip button 90 for the circuit breaker 33 is mounted just alongside and to the right of the knife switch 32 so that the button 90 is operated last in the ordinary operation of the device.

The trip button 90 may be replaced by a lever which is operated only when the handle of the knife switch 32 is moved to full open position; so that when the operator finally reaches knife switch 32 which is the last of the knife switches to be opened and completes the opening of the same, the pushing of the handle thereof to the full open position will result in tripping of circuit breaker 30. In ordinary cases, however, the placement of the push button 90 at the end of the switching device 2| to the right of the last knife switch 32 is sufiicient.

As seen in Figure 6, push button 90 is arranged so that it is in series with a direct current source 9 I and the coil 92. On pushing in the push button 90, closing coil 92 is disconnected from the current source 9| and spring 93 may now effect the tripping operation of the circuit breaker 30. This is shown only schematically. It is obvious, of course, that a push button may be so arranged that it will connect a trip coil of the circuit breaker across an appropriate current source to trip the circuit breaker rather than disconnect a closing coil of the circuit breaker.

In the event the device is such that the operation of the push button 93, either directly or by mechanical means interlocked with the switch 32, will trip the circuit breaker 30.

The circuit breaker 36 is more fully described in Patent No. 2,355,075 and as shown partially in Figures 1, 2 and 3, has a housing for the operating mechanism and the contacts, which hOllSiIlg is insulatedly supported from the buses 24 and 25. The contacts comprise a bridging contact 91 mounted on a contact lever 96 operated by the handle 98 to closing position to bridge contact elements 99 and :20, which are connected respectively to buses 25 and 24.

Any are which is drawn may be readily extinguished by the arc extinguisher II.

It will thus be seen that in operation my switch device 2! is brought up or located adjacent to the cell which is to be replaced. Connectors from buses 24 and 25 are placed across the cell. The circuit breaker 30 is closed; then the knife switches 32 to 37 are closed in that order thus placing seven parallel circuits across the buses 24 and 25 and therefore across the cell ll. Cell H is removed and repaired or replaced and then replaced between the bus sections l8 and IS in series with the remaining cells.

The switches are opened sequentially, knife switch 31 being opened first and knife switch 32 last, and then the circuit breaker 30 is tripped by the operation of the push button 90. The switching device 2| may thus readily be connected across the cell I l and then disconnected after the cell II is replaced; and when connected, with the cell ll withdrawn, it may carry the full 70,000 ampere current at 8 volts owing to the plurality of parallel connectors.

After the cell I l is inserted in parallel with the entire switching device, then the switches as they are opened need not interrupt the full current and may readily be opened sequentially, gradually to decrease the number of parallel circuits across the cell II and thus finally to place the cell l l in series with the other cells.

Accordingly the circuit breaker 30 when it is finally tripped, interrupts a relatively low current since by this time the cell II which is an electrolytic cell has begun to operate and has a relatively low resistance.

Accordingly the circuit breaker 30 need be one which is adapted only to carry approximately 1500 amperes under normal conditions and need not be adapted to carry as heavy a current as 70,000 amperes.

By this means, therefore, the multiple connector in the specific embodiment shown comprises seven separate connectors mounted togather and is much less cumbersome and much less expensive than a single connector or interrupter adapted to carry the full 70,000 amperes.

In the foregoin I have described my invention only in connection with a specific embodiment thereof. Since many modifications and variations of my invention should now be obvious to those skilled in the art, I prefer to be bound not by the specific disclosures herein but only by the appended claims.

7 IVE-"claim: Y

A 's'witching device f-or "sequentially" estabihshingand discon-meeting :a plurality of parallel circiii ts: across an electrolytic cell in series I with so her-electrolytic cells; said switchingdeviceeoma z pr-i'sing :a: support-ya plurality of switches earned by said support; a handleindividual-to eachwof isaid -switchesp and "an .int'erlock member carried ii-bye ea'ch handle; each interlock member. being engageablewith the interlock memberoi anwadjacent switch; the "interlock member ofoneswitch iibe-i'ng arranged to block the movementf'of theinw 1bckmember andhandleo'f an adjacent switch when: the handles are :in one. position;=.and the :iintrlock member of said adjacent switchbeing tiswitchescarried-by said support; a handle indidual to. eachof said switches; and an interlock :Yinembercarriedby-each handle; each interlock member being engageable with the interlock Fmember' of: anadjacent switch; the interlock, a

%:member 'of-ones'switch being arranged to block ithekmovementof the interlock member and hancrdle of an' adja'cent'switch when 'the handles are (ti-n1 *oneugposition; and the interlock member of said 3- adjacent "switch: being arran'ged' toblock mov'ementbf the interlockmember and handle eoix-said ifirst mentioned switch when the handles .iraretimanother position, each of said switches beitstacross' an electricaldevice; a plurali-ty*of ing arranged on operation of the: handle to 'esl t'ablish or disconnect-onset said :parallel "circuits, s'aid switching device having aypair ofconductor's;

said switches each having apair of terminals; one

--terminal ofeachi switchbeing connected toone conductor theother terminal; ofeeach' switch being "connected to the other-conductor forcon- Y nection oi said'sw-itc-hing --device-acrcss" said electrical device, a circuit breaker-inemb'er mounted acrossfsaidi conductors; and means' for opening said circuit breaker member after 'al lrof theother switcheshave been opened; "said circuit. breaker member having an "arc extinguisher.

3.1 :Inaa switching device for use for by-passing electrical apparatusin an electricalcircuit; a'plu- 1"a=lity "of manually operated switches connected in parallel;- a circuit breaker connected in parallel withsa'id switches,:.:said"switchesand circuit breaker being connected across the terminals of said: electrical apparatusto be by-passed,*the combined current carrying capacity 'of said switches andicir'cuit breaker being suiiicie-nt to carry the: full current 'flowing im said circuit :and said circuit-breaker having a current carrying ca- -pacity considerablyless than the-current of said "cir'cuitxbut able to carry-sai'd-cu'rrent for a short interval of time while the contacts of said switches are b'eing closed; remotely operatedmeans for up- =-erating said circuit breaker to controlthe closing ."of said circuitbreaker before any'of said switches (are closed' and for controlling the opening of'said circuit breaker after all the other switches have "been-opened, and are extinguishing means for said circuitbreaker.

WILLIAM DEANS.

REFERENCES CITED .The following reference's'are oi record-in the I .file of this patent:

' UNITED STATES PATENTS Numb er Name Date 1,465,384 Wes'c'oat Aug. 21, 1923 .-2,34,9. ,631'

iLindstromet-al. May 23, 1-944 

